Furnace slot cover and operating mechanism



Jan. 20, 1959 A. J. BOLAND, SR., E'AL FVURNACE SLOT COVER AND OPERATING MECHANISM Filed July 3, 1953 2 Sheets-Sheet J.

HTToQ/vffs Jan. 20, 1959 A. J. BOLAND, SR., ET AL FURNACE SLOT COVER AND OPERATING MEOHANISM Filed July 5, 1955 2 Sheets-Sheet 2 United tates Patent G l FURNACE SLOT CVER AND OPERATING MECHANISM Albert J. Boland, Sr., andvAlbert J. Boland, Jr., Webster Groves, Mo.

Application July 3, 1953, SerialNo. 366,036

2 Claims. (Cl. 26S-e8) Thepresent invention is directed to improvements in the roof structure of enameling furnaces ofthe box type, wherein an overhead conveyor is utilized for introducing were into the furnace, and for withdrawing the ware theref from after processing has been completed. I More specifically, this invention relates to novel mechanismadapted to prevent' heat losses in a box type enameling furnace during intervals obtaining between ware proce essing operations, and. more importantly, during protracted periods of time, such as an overnight shutdown of the furnace. The type of furnace herein under consideration is well known. Itv is provided with. a longitudinally extending roofA slot through which the depending ware suspension hangers of an overhead conveyor project into the heat chamber. A preferable embodiment of such a roof construction isillustratedrand described in United States Letters Patent No. 2,156,008, issued to one of the co-inventors ofthe present invention on April 25, 1939..

TheA primary object of the instant invention is to provide a cover for a roof slot of the character disclosed in said patent, which cover is pivotally mounted for swinging movements from a horizontal or slot sealing position toa perpendicular or slot uncovering position, and vice versa.v i Itis a further object of the invention to provideinovel operating mechanism for actuating said cover tothe lse-` lected'dlsposition thereof by means of linkage controlled by .an;air cylinder includedin a conventional compressed air system.

` Thecover member is in the form of an elongated plate, preferably but not necessarily of stainless steel, whichy overlies and is longitudinally coextensive with the roof` slot 'Means are provided for` supporting the plate from one'or more pivotal mountingg. and incidentallyalso, the number of operating mechanismsbeing dependentonthe length. of the furnace. l

When the furnaceis in operation, at which time ,the hangers of the overhead conveyor have free movement in the slot, the cover member is maintained in vertical or opemdisposition, having been previously elevated to such position by an air cylinder controlled linkage included in the operating mechanism. When the furnace is not in operation, vat. which time the conveyor and its hangers arenot'in use as is understood, the cover member is maintained in horizontal or closed disposition, following the lowering thereof to. such positionby thelinkage aforesaid.

A more comprehensive understandingof the invention, its advantages and Inode of operation, may be hadfrom the' detailed descriptionthereof to follow withreference to the accompanying two sheets of drawings, wherein a preferred embodiment of the inventionis portrayed..

` In said drawings:

Figure 1 isafragmentary top planview of thev front end' of a box type enameling furnacefrequippedwiththe slot cover and operating mechanism therefor comprising the present invention, said slot cover being in closed "ice disposition, and the insulation which covers the roof of the'furnace being omitted on the` left hand half thereof;

Figure 2 is a vertical sectional view through the furnace roof taken approximately along the line 2-2 of Figure l, illustrating the slot cover in open disposition, and including the insulation which covers the left hand half ofthe roof;

Figure 3 is a fragmentary vertical sectional view on an enlarged scale, taken along the line 3--3 of Figure l, the roof insulation being included;

Figure 4 is a fragmentary top plan view of a portion of'Figure 3; and;

Figure' 5 isv a view similar to Figure 3 illustrating the cover and operating mechanism disposed as in Figurey 2. i ln the drawings, only the upper portion of a box type mufe furnacer generally designated l is shown, inasmuch asthe present invention is concerned only with mechanism associated with the roof -construction of said furnace. Asalso illustrated and more fully described in said Patent No. 2,156,008, the furnace Titi includes side walls 12 reinforced by vertical steel columns 14, longitudinally spaced,V transverse I-beams 16 mounted atop the columns 14 for supporting the roofl structure and the conveyor guide rail 18, longitudinal channel members 20 lwelded or otherwise rigidly secured to the lower anges i of the I-beams 1,6, and arch brackets 22 which are secured to and supported from the channel members 2t).

TheA arch brackets22 are arranged transversely of the furnace', andare spaced apart at regular intervals as demonstratediin the left hand half of Figure l. Furthermore, these brackets are mounted in pairs, as shown par ticularly in Figure 2, the inner endsof each pairv being spaced apart to provide between them a clearance or' longitudinal roof slot 24, best seen in Figures 3 through y 5, And as also seen to best advantage in Figures `3 and 5, the arch brackets are each provided at the bottom with a horizontal flange 26 engaging an inverted T-slot 27 formed in the upper partrof the refractory tiles 28, whereby said tiles are suspended from said brackets.

Suitable insulation Cittv covers the roof of the furnace to prevent loss of heat, as is understood. The upper portion of the roof slot 24 is faced with alloy slot cast-V ings 32 having laterally projecting flanges 3ft which are bolted as shown, or otherwise secured to horizontal seats 36 provided for that purpose on the arch brackets 22. Means are provided for maintaining the slot castings in longitudinal alignment, and insulation material also fills the .clearance spaces whichrmay obtain between said castings and the ends of the arch brackets, all as clearly disclosed in said patent.

AThe upper ends 38 of the face plate portions of the slot castings terminate above the flanges 34 to provide a slideway for platestll, which, as shown in Figure 2, cover theslot 24 when ware suspended from a suitable overhead conveyor generally designated i, is being treated in the heatchamber. The conveyor 42 travels reciprocably along the guide rail 18, and includes depending hang@ ers 44 from which the ware is suspended, as is understood. The cover lplates 40 may be mounted on the conveyor in any suitablemanner.

The 'mechanism comprising the present invention is mounted,v above the furnace roof, and is designated gen-v orally by the numeral Sil. lt includes a dat cover plate S2, preferably of stainless steel and coextensive with the roof slot 24; an arm 54 to the underside of which the cover lplate is rigidly secured; a pivotal connection 55 for one/endet said arm with an angular bracket 58 rigidly secured tothe lateral liange 34 of one ofhthe slot castings; linkage including an angularly disposed turnbuckleadjustable operating rod 69 the lower end of which has a and the upper end of which has a similar connection 63 with one arm 64 of a V-shaped lever 66; a stub shaft 68 mounted in a bracket 69 for rotatably supporting the lever 66; a substantially horizontally disposed turnbuckleadjustable operating rod 70 having a pivotal connection 72 at one end with the other arm 74 of lever 66; an air cylinder 76; and a coupling sleeve 78 connecting the other end of the rod 70 to the projecting end of the air cylinder piston rod 80.

The bracket 69 is rigidly secured to a longitudinally extending base plate 82, which is welded or otherwise attached to and supported on the upper flanges of the transverse I-beams 16, as shown particularly in Figure -1. The air cylinder 76 is provided with laterally projecting trunnions 84 which extend into circular openings provided therefor in the vertical legs of a pair of angle brackets 86, whereby to accommodate tilting movements of said cylinder. The angle brackets 86 are secured to and supported on a longitudinally extending base member 88, illustrated in the drawings as being of I-beam contour. The member 8S, similarly to the member 82, is welded or otherwise Secured to and supported on the upper flanges of the transverse beams 16.

The air cylinder 76 is of conventional design, and is operable in the usual manner, as will be explained. It is included in a conventional compressed air system of the reversible type, not deemed necessary to illustrate in its entirety. Air under pressure from a source of power may be supplied to the cylinder 76 via line 9()v to effect the closing of the cover plate S2, and to maintain such disposition thereof indeiinitely. Similarly, air under pressure from said power source may be supplied to cylinder 76 via line 92 to effect the elevation of said cover plate, and to maintain such disposition thereof indefinitely.

In other words, line 90 serves in air inlet capacity during slot closure operations, and in an exhaust capacity during slot uncovering operations, and vice versa with respect to the line 92, as should be evident. Reversal of air pressure is effected by means of a conventional control valve, either manually or mechanically operable in well understood fashion.

Operation Although the manner in which the invention operates is considered evident from the foregoing description and an inspection of the drawings, a brief explanation will now be presented.

it is to be borne in mind that in the preceding detailed description, reference has been had to but one mechanism 50. However, it should be readily apparent that the number of such mechanisms is governed by the length of the furnace, `so that the invention contemplates as many longitudinally spaced installations as may be required for smooth operation.

Assuming now that the furnace is to be placed in operation, the control valve of the pneumatic system would be actuated to transmit air under pressure to cylinder 76 via line 92 to retract the piston rod 80, whereby to elevate the cover 52 to the position thereof exhibited in Figures 2 and 5. With the cover plate 52 thus perpendicularly dispositioned, reciprocal movements of the Ware suspending conveyor 42 may be had, as should be apparent. it is to be noted that the coupling element 78 has a dual role, in that it not only serves to connect the operating rod 70 and the piston rod 80, but also serves as an adjustable abutment element to limit the movement of said piston rod in a leftward direction, as viewed in the drawings.

Assuming now that the furnace 10 is to be shut down temporarily, or for a lengthy period of time, the control valve of said pneumatic system would be actuated to transmit air under pressure to cylinder 76 via line 90 to advance the piston rod 80, whereby to lower the cover 52 to the closed position thereof exhibited in Figures 1, 3, and 4.

It is noted that the trunnion mounting of the air cylinder 76 together with the disclosed turnbuckle adjustability of the operating linkage is conducive to smooth and ecient operability of the mechanism.

In view of the foregoing description augmented by an inspection of the drawings, it is believed that an adequate disclosure of the concepts of this invention has been presented. It is to be understood, however, that the structural details illustrated and described have been given in an exemplary rather than in a limiting sense, the invention contemplating any and all modifications and equivalents which may fall within the scope of the appended claims.

What is claimed is:

l. In a muffle furnace having a roof slot from end to end: conveyor support means above the roof slot; a conveyor to travel along the support means while depending through the slot, said conveyor being provided with a connected cover member moving with said conveyor for closing said slot when the conveyor depends therethrough; an elongated cover plate adapted to iit over the slot when the conveyor is not depending through the slot; means connecting the cover plate with the furnace for movement of the cover plate into position between the conveyor support means and the furnace to cover the slot, and for movement away from the slot independently of the movement of the conveyor to permit travel of the conveyor along the slot, said means including a stationary hinge connecting one end of the cover plate to the roof; power means, and means connecting the power means and the cover plate to produce the previously described movement of the plate by energizations of the power means.

2. In a muievfurnace having a roof slot from end to end: conveyor support means above the roof slot; a conveyor to travel along the support means while depending through the slot, said conveyor being provided with a connected cover member moving with said conveyor for closing said slot when the conveyor depends therethrough; an elongated cover plate adapted to fit over the slot when the conveyor is not depending through the slot; means connecting the cover plate with the furnace for movement of the cover plate into position between the conveyer support means and the furnace to cover the slot, and for movement away from the slot independently of the movement of the conveyor to permit travel of the conveyer along the slot; said means including a stationary hinge connecting one end of the cover plate to theroof; powermeans, and means connecting the power means and the cover plate to produce the previously described movement of the plate by energization of the power. means, said last named means comprising a mechanical linkage with adjusting means in the linkage to adjust the length thereof and thereby provide for proper seating of the cover plate, -said linkage including a rst link connected at one end to the power means, a rocker member rockably mounted on the furnace and pivotally connected to the other end of the first link, a second link connecting the rocker member and the cover plate, and the adjusting means is one to adjust the length of oneof the links, and said power means including a pneumaticmotor having a cylinder and a linear piston connected to the first link, and a rockable mounting for the cylinder..

References Cited in the le of this patent UNITED STATES PATENTS 

